Along with the popularization of the optical wavelength division multiplexing transmission, the wavelength-selective switch for multiplexing or demultiplexing an optical signal for each wavelength is a key device of optical communication.
A schematic configuration diagram of an optical switch module is shown in FIG. 7. An optical switch module 211 has a virtually imaged phase array (VIPA) 201, collimate lenses 212a and 212b, a semi-cylindrical lens 212c, a focus lens 213, a micro mirror array 214, an optical input/output port 215, connectors for optical fiber 215a and 215b, optical fibers 215c and 215d, a metal casing 217 and supporting tables 218a to 218e, for example.
The optical switch module 211 has two optical ports, emits light from end faces of the optical fibers 215c and 215d to make the same parallel light by the collimate lenses 212a and 212b, and thereafter the light converges on the VIPA 201 by the semi-cylindrical lens 212c to enter. The VIPA 201 emits the light by maintaining separate emission angles according to wavelengths λ1 to λn. The focus lens 213 focuses two lights on one point on a micro mirror of the micro mirror array 214. The micro mirror array 214 has a plurality of micro mirrors corresponding to the wavelengths λ1 to λn. By changing the angle of the micro mirror, an optical path of the entered light may be returned to the optical path of the light for each of the wavelengths λ1 to λn or reflected to the optical path of the light, and switching for each wavelength of the light may be performed between the two optical ports.
Patent Document 1: Japanese Patent Application Laid-Open No. 2004-258409.
However, the conventional wavelength-selective switch has a problem that a position of an optical component easily shifts when fixing the optical component with adhesive and by soldering. Also, in the conventional wavelength-selective switch, when the position of the optical component is shifted and fixed, it is difficult to return the same to an original position. Further, in a case of fixing with adhesive and by soldering, at an operational temperature of the conventional wavelength-selective switch, for example, the operational temperature from −5° C. to 70° C., the position of the optical component might shift due to an effect of thermal stress to adhesive and soldering, so that there are some concerns about long-term use.